Programming instructions

TTL

Multisim Component Reference Guide 6-22 ni.com

Data selector/multiplexer truth table:

6.4.44 74xx158 (Quad 2-to-1 Data Sel/MUX)

This device contains inverters and drivers to supply full on-chip data selection to the four

output gates. It presents inverted data to minimize propagation delay time.

A 4-bit word is selected from one of two sources and is routed to the four outputs.

Data selector/multiplexer truth table:

6.4.45 74xx159 (4-to-16 Dec/DEMUX (OC))

This 4-line-to-16-line decoder uses TTL circuitry to decode four binary-coded inputs into one

of sixteen mutually exclusive open-collector outputs when both the strobe inputs are low.

The demultiplexing function is performed by using the 4 input lines to address the output line,

passing data from one of the strobe inputs with the other strobe input low.

STROBE SELECT OUTPUTS

A/B ABY

1 X XX0

00 0X0

00 1X1

01 X00

01 X11

STROBE SELECT OUTPUT

A/B ABY

1 X XX1

000X1

001X0

01X01

01X10

ComponentRef.book Page 22 Thursday, December 7, 2006 10:12 AM